More than 500 volunteers flocked to a remote bay in New Zealand in response to a devastating mass stranding of pilot whales.

Around 416 pilot whales beached near the base of Farewell Spit in Golden Bay overnight, of which 250 to 300 were already dead when the whales were discovered, the Department of Conservation announced in a Feb. 10 media release.

A witness told The Washington Post that the whales were "crying and sighing" as they lay stranded on the beach.

Friday's incident was the third largest whale stranding ever recorded in New Zealand and the largest known whale stranding in the country since 1985, when 450 were stranded in Auckland, Reuters reported.

Rescuers tried to refloat the remaining cetaceans during high tide on Friday morning but only had partial success. Around 50 whales had swum out of the bay but 80 to 90 had re-stranded on the beach by the afternoon.

Andrew Lamason, Department of Conservation operations manager for Golden Bay, told The Guardian it was common for whales involved in a mass stranding to re-beach themselves because they are very social animals who like to stay in close proximity to their pod.

"We are trying to swim the whales out to sea and guide them but they don't really take directions, they go where they want to go. Unless they get a couple of strong leaders who decide to head out to sea, the remaining whales will try and keep with their pod on the beach," he said.

The rescue team has been pouring water over the re-stranded whales to try and keep them cool before floating them out at the next high tide. Children also sang songs to keep the creatures calm.

"I've never seen anything like this," a volunteer named Petra Dubois told Stuff.co.nz. "It's just so unbelievably sad to see all these bodies; so many lives gone and so many that might not survive. Just so devastating, I really don't know what to say."

Lamason explained to The Guardian that many volunteers were working around the clock in chilly temperatures and mentally traumatic conditions.

"It is cold, it's wet and some of us have been in and out of the water for nine hours now. We can only cope with robust volunteers, not ones that are going to break down, which happens quite often," he said.

According to RadioNZ, the effort to refloat the remaining 80 to 90 whales will resume Saturday. The whales will be kept comfortable and can survive for several days as long as they are kept cool and wet.

The cause of the stranding is unclear. However, Lamason said that the bay was prone to mass strandings due to the area's shallow waters that can confuse the mammals' sonar and find it difficult to get back out.

In an interview with RadioNZ, Otago University zoologist Liz Slooten ruled out seismic blasting as a cause since the last survey in the area was done nearly a week ago. The blasting of seismic testing can potentially disorientate whales.

She added that the cause of the latest mysterious stranding may never be known.

According to Project Jonah, "strandings are complex events and there are many reasons why dolphins and whales may strand. In most cases the exact cause is unknown but any one of the following factors, or a combination of them, can be the cause."

Pilot whales are not considered to be endangered even though they are depleted in some areas. The American Cetacean Society stated, "There are likely to be almost a million long-finned pilot whales and at least 200,000 short-finned pilot whales worldwide."

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Ninety-five false killer whales were stranded off the coast of Hog Key in Florida's Everglades National Park over the weekend.

The National Oceanic and Atmospheric Administration (NOAA) wrote in a Facebook post this morning that 82 animals are now confirmed dead and 13 are unaccounted for. Earlier reports put the death toll at 81.

Officials told the Miami Herald that this is the largest recorded stranding of such species in Florida.

False killer whales belong to the dolphin family and get their name due to their resemblance to orcas. Females reach lengths of 15 feet and males are almost 20 feet. Adult false killer whales can weigh approximately 1,500 pounds.

The U.S Coast Guard first spotted the stranding on Saturday near Hog Key, which is located in a dense network of islands off south west Florida.

According to the Palm Beach Post, a rescue team reached the false killer whales—which included adults, juveniles and calves—by Sunday but could not save the vast majority of them.

"Once on the scene, the response team attempted to herd the whales into deeper water, however, they were ultimately unsuccessful in that effort," NOAA's mammal stranding network Blair Mase explained to the publication.

Mase said that the false killer whales were beached and scattered along the shoreline in poor condition and "deeply embedded in the mangroves," making the effort to rescue them nearly impossible. Rescuers had to humanely euthanize nine of the animals. Seventy-two of the dolphins died on their own on Sunday.

NOAA said that response teams are now working to assess the scene, but its remote location makes it challenging to gain access. The National Park Service is conducting aerial flyovers to help make it easier for the response teams to enter the area by boat.

It is currently unclear why the massive stranding occurred. In the coming months, biologists will conduct necropsies to determine what exactly happened, NOAA said.

Local marine biologist Stefanie Wolf told FOX 4 Now that one theory behind the stranding could be due to the pod getting lost and entangled in the area's thick maze of mangroves.

"Down in that area of Everglades National Park it's very shallow—very easily for even a human to get lost navigating through those waters," Wolf said, adding that the pod might not have been able to use their echolocation to find their way around.

As the FOX 4 reporter noted, while strandings are rare, when they do happen they usually happen in large groups because the dolphins are social animals.